/*
 * Copyright 2002-2013 the original author or authors.
 *
 * Licensed under the Apache License, Version 2.0 (the "License");
 * you may not use this file except in compliance with the License.
 * You may obtain a copy of the License at
 *
 *      http://www.apache.org/licenses/LICENSE-2.0
 *
 * Unless required by applicable law or agreed to in writing, software
 * distributed under the License is distributed on an "AS IS" BASIS,
 * WITHOUT WARRANTIES OR CONDITIONS OF ANY KIND, either express or implied.
 * See the License for the specific language governing permissions and
 * limitations under the License.
 */

package org.springframework.web.context.support;

import org.springframework.beans.factory.config.ConfigurableListableBeanFactory;
import org.springframework.context.support.StaticApplicationContext;
import org.springframework.core.env.ConfigurableEnvironment;
import org.springframework.core.io.Resource;
import org.springframework.core.io.support.ResourcePatternResolver;
import org.springframework.ui.context.Theme;
import org.springframework.ui.context.ThemeSource;
import org.springframework.ui.context.support.UiApplicationContextUtils;
import org.springframework.web.context.ConfigurableWebApplicationContext;
import org.springframework.web.context.ServletConfigAware;
import org.springframework.web.context.ServletContextAware;

import javax.servlet.ServletConfig;
import javax.servlet.ServletContext;

/**
 * Static {@link org.springframework.web.context.WebApplicationContext}
 * implementation for testing. Not intended for use in production applications.
 *
 * <p>Implements the {@link org.springframework.web.context.ConfigurableWebApplicationContext}
 * interface to allow for direct replacement of an {@link XmlWebApplicationContext},
 * despite not actually supporting external configuration files.
 *
 * <p>Interprets resource paths as servlet context resources, i.e. as paths beneath
 * the web application root. Absolute paths, e.g. for files outside the web app root,
 * can be accessed via "file:" URLs, as implemented by
 * {@link org.springframework.core.io.DefaultResourceLoader}.
 *
 * <p>In addition to the special beans detected by
 * {@link org.springframework.context.support.AbstractApplicationContext},
 * this class detects a bean of type {@link org.springframework.ui.context.ThemeSource}
 * in the context, under the special bean name "themeSource".
 *
 * @author Rod Johnson
 * @author Juergen Hoeller
 * @see org.springframework.ui.context.ThemeSource
 */
public class StaticWebApplicationContext extends StaticApplicationContext
        implements ConfigurableWebApplicationContext, ThemeSource {

    private ServletContext servletContext;

    private ServletConfig servletConfig;

    private String namespace;

    private ThemeSource themeSource;


    public StaticWebApplicationContext() {
        setDisplayName("Root WebApplicationContext");
    }


    /**
     * Set the ServletContext that this WebApplicationContext runs in.
     */
    @Override
    public void setServletContext(ServletContext servletContext) {
        this.servletContext = servletContext;
    }

    @Override
    public ServletContext getServletContext() {
        return this.servletContext;
    }

    @Override
    public void setServletConfig(ServletConfig servletConfig) {
        this.servletConfig = servletConfig;
        if (servletConfig != null && this.servletContext == null) {
            this.servletContext = servletConfig.getServletContext();
        }
    }

    @Override
    public ServletConfig getServletConfig() {
        return this.servletConfig;
    }

    @Override
    public void setNamespace(String namespace) {
        this.namespace = namespace;
        if (namespace != null) {
            setDisplayName("WebApplicationContext for namespace '" + namespace + "'");
        }
    }

    @Override
    public String getNamespace() {
        return this.namespace;
    }

    /**
     * The {@link StaticWebApplicationContext} class does not support this method.
     *
     * @throws UnsupportedOperationException <b>always</b>
     */
    @Override
    public void setConfigLocation(String configLocation) {
        if (configLocation != null) {
            throw new UnsupportedOperationException("StaticWebApplicationContext does not support config locations");
        }
    }

    /**
     * The {@link StaticWebApplicationContext} class does not support this method.
     *
     * @throws UnsupportedOperationException <b>always</b>
     */
    @Override
    public void setConfigLocations(String[] configLocations) {
        if (configLocations != null) {
            throw new UnsupportedOperationException("StaticWebApplicationContext does not support config locations");
        }
    }

    @Override
    public String[] getConfigLocations() {
        return null;
    }


    /**
     * Register request/session scopes, a {@link ServletContextAwareProcessor}, etc.
     */
    @Override
    protected void postProcessBeanFactory(ConfigurableListableBeanFactory beanFactory) {
        beanFactory.addBeanPostProcessor(new ServletContextAwareProcessor(this.servletContext, this.servletConfig));
        beanFactory.ignoreDependencyInterface(ServletContextAware.class);
        beanFactory.ignoreDependencyInterface(ServletConfigAware.class);

        WebApplicationContextUtils.registerWebApplicationScopes(beanFactory, this.servletContext);
        WebApplicationContextUtils.registerEnvironmentBeans(beanFactory, this.servletContext, this.servletConfig);
    }

    /**
     * This implementation supports file paths beneath the root of the ServletContext.
     *
     * @see ServletContextResource
     */
    @Override
    protected Resource getResourceByPath(String path) {
        return new ServletContextResource(this.servletContext, path);
    }

    /**
     * This implementation supports pattern matching in unexpanded WARs too.
     *
     * @see ServletContextResourcePatternResolver
     */
    @Override
    protected ResourcePatternResolver getResourcePatternResolver() {
        return new ServletContextResourcePatternResolver(this);
    }

    /**
     * Create and return a new {@link StandardServletEnvironment}.
     */
    @Override
    protected ConfigurableEnvironment createEnvironment() {
        return new StandardServletEnvironment();
    }

    /**
     * Initialize the theme capability.
     */
    @Override
    protected void onRefresh() {
        //初始化主题
        this.themeSource = UiApplicationContextUtils.initThemeSource(this);
    }

    @Override
    protected void initPropertySources() {
        super.initPropertySources();
        WebApplicationContextUtils.initServletPropertySources(
                this.getEnvironment().getPropertySources(), this.servletContext, this.servletConfig);
    }

    @Override
    public Theme getTheme(String themeName) {
        return this.themeSource.getTheme(themeName);
    }

}
